This invention relates to a tubular flexible remote control in which one or more push-pull blades are slidable lengthwise in the tubular sheath on spaced rolling elements disposed on opposite sides of each blade.
Illustrative of such a flexible remote control is that disclosed in U.S. Pat. No. 2,841,029 to Richoux in which the balls are spaced from one another by cage strips having openings to hold the individual balls. Metal ball-cage strips of the type disclosed by Richoux are relatively expensive to make, are comparatively heavy and suffer from the fact that their metal necessarily rubs with other metal elements of the control. U.S. Pat. No. 3,667,313 was granted to Young for the improvement of ball-cage strips made of flexible plastic. However, flexible remote controls have heretofore depended on a single line or series of spaced ball bearings in contact with each side of a push-pull blade to provide facile movement of the blade. The stack formed by two lines of balls and a push-pull blade between the two lines of balls is inherently an unstable arrangement which tends to become operatively less reliable as the load on the push-pull blade is increased. This tendency is augmented when the remote control has more than one push-pull blade as disclosed in U.S. Pat. No. 3,552,218 to Gregory.
Accordingly, the object of this invention is to provide an improved arrangement of ball bearings and push-pull blades in tubular flexible remote controls that overcomes the undesirable instability of the arrangement used heretofore.